1. Technical Field
The present invention relates to a thrust bearing suitable for a turbocharger of an internal-combustion engine having improved seizure resistance.
2. Background of the Invention
A rotating shaft for a turbocharger of an internal-combustion engine is supported by a radial bearing and a thrust bearing located in a bearing housing. A turbine blade is fixed on an end of the shaft, and a compressor blade is fixed on the other end. The thrust bearing is engaged with a thrust collar and located. When the thrust collar integrated with the turbine blade is rotated at a high speed during operation of the turbocharger, the thrust bearing is slid against the thrust collar.
Consequently, resistance to corrosion and abrasion is required for a sliding portion of the thrust bearing that slides on the thrust collar. As a material for the sliding portion of the thrust bearing, used is brass in which a Mn—Si-based compound (hereinafter referred to as “needle-like Mn—Si-based compound”) deposited in a needle shape in a brass matrix is dispersed, as disclosed in JP-A-2003-42145. JP-A-2003-42145 discloses that abrasion resistance of the thrust bearing is improved by arranging so that a length direction of the Mn—Si-based compound is parallel to a surface of the sliding portion in the thrust bearing.